<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>2_受控组件</title>
</head>
<body>
    <!-- 准备好一个“容器” -->
    <div id="test1"></div>
    <!-- 引入react核心库 -->
    <script type="text/javascript" src="../js/react.development.js"></script>
    <!-- 引入react-dom，用于支持react操作DOM -->
    <script type="text/javascript" src="../js/react-dom.development.js"></script>
    <!-- 引入babel，用于将JSX转为JS -->
    <script type="text/javascript" src="../js/babel.min.js"></script>
    <script type="text/babel">
        //创建组件
        class Login extends React.Component{
            //初始化状态
            state = {
                username:'',//初始化用户名
                password:'',//初始化账号
            }
            //保存用户名到状态中
            saveUsername = (event)=>{
                this.setState({username:event.target.value})
            }
            //保存密码到状态中
            savePassword = (event)=>{
                this.setState({password:event.target.value})
            }
            //表单提交的回调函数
            handleSubmit= (event) =>{
                event.preventDefault()//阻止表单提交
                console.log(this)
                const {username,password} = this.state
                // const {username,password} = this
                // alert('您输入的用户名是：'+ username.value + '您输入的密码是： ' + password.value)
                alert('您输入的用户名是：'+ username+ '您输入的密码是： ' + password)
            }

            render(){
                return(
                    <form action="" onSubmit={this.handleSubmit}>
                        <span>姓名：</span>
                        <input onChange = {this.saveUsername} type="text" name="username"/>
                        <span>密码：</span>
                        <input onChange = {this.savePassword} type="password" name="password"/>
                        <button>登录</button>
                    </form>
                )
            }
        }
        //渲染组件到页面
        ReactDOM.render(<Login/>,document.getElementById('test1'))
    </script>
</body>
</html>